How to compile scss to css on npm start

I am unable to compile scss files to css once the application is run using npm start. Is there a way to live reload a sass to css like ts are compiled to js by utility tsc:w.So I have to stop the build and then do gulp watch or node-sass command to compile scss to css and then build solution again using npm start. I tried below approaches but none worked.
Here is the code in package.json: